The invention relates to a household dishwasher for washing dishes in one or more water-conducting wash sub-cycles and for subsequently drying the dishes in at least one subsequent drying cycle of a wash cycle to be performed.
In conventional dishwashers an electric water heater is generally provided, in particular with at least one electric heating resistor, in order to be able to heat a quantity of water introduced in each instance into the wash container of the dishwasher for at least one water-conducting wash sub-cycle, for example for the cleaning cycle and/or final rinse cycle, of a wash cycle to be performed, to a required temperature. It can be configured for example in the form of a flow-through heater. It is preferably a component of the liquid circulation circuit of the dishwasher, which comprises in particular a circulating pump, in some instances a water switch for the selective coupling of feed tubes leading to a number of spray facilities to the outlet tube of the circulating pump, one or more spray facilities, a pump sump positioned on the bottom of the wash container, in which the wash liquid sprayed out by the one or more spray facilities collects in the wash container, and/or in some instances valves, liquid connecting lines, etc. The water heater can be housed in particular in the housing of the circulating pump, thereby forming what is referred to as a heat pump. The mode of operation of a water heater is based in particular on the principle of the electric resistance heater, in which electrical energy is converted to thermal energy, which is transferred to the water flowing past or in the water heater. In practice what is known as a tubular heating unit can be used, being located preferably in a water-conducting tube, in particular a tube through which water flows. Alternatively a tube segment can also be provided, for example, having at least one tubular heating unit or what is referred to as a thick-layered conductive heating track on the outside, with water flowing through its interior when the circulating pump of the dishwasher is activated. The heating of the quantity of water introduced into the wash container for the performance of the respective wash sub-cycle, for example the cleaning cycle and/or final rinse cycle, to a required minimum temperature requires the generation of a specified thermal energy or heat energy by the electric resistance heater, which involves a corresponding electrical energy requirement. It is desirable to keep this electrical energy consumption as low as possible.